Pharmaceutical dispensing system with coordinate guidance

ABSTRACT

The invention describes improved methods and mechanisms for providing secure access to pharmaceutical and supply items in a clinical setting. In one version of the invention, a dispensing unit has an interior housing one or more drawers. Each drawer has one or more storage locations. The fronts of the drawers are covered with one or more locking doors, preventing access to a particular drawer, unless the covering door is unlocked. Indicators are mounted on the side of the enclosure, to guide the user to a drawer covered by an associated unlocked door. The unit further includes indicators on the sides of the drawers, to guide the user to the right storage receptacles or pockets within the drawer. Some pockets may have lids. Some of the lids may have locks. Sensors associated with at least some of the individual pocket lids may be provided to detect the lifting of a lid. Means to automatically detect the entry of a hand or fingers into a pocket may be provided. One or more loudspeakers may be mounted on the unit, to provide auditory guidance and confirmation of correct access, by sounds and voice prompts. One or more video cameras may be mounted on the unit. A processor is mounted in the unit, or, in the case of an auxiliary unit, the auxiliary unit is connected to the processor on the main unit. The processor is connected to receive signals from sensors in the dispensing unit, from the video camera, and to send signals to the indicators, and to send auditory information to loudspeakers which are designed to focus the sound specifically to the user. Modular locking drawers may be mounted in this unit also, dispensing individual doses using a method where the drawer has to be fully closed for each unit dose of medication taken.

This application claims benefit of priority to U.S. ProvisionalApplication No. 60/866,081 filed Jan. 22, 2007 which is incorporated byreference herewith in its entirety.

BACKGROUND OF THE INVENTION

The invention describes improved methods and mechanisms for providingsecure access to pharmaceutical and supply items in a clinical setting.

In large medical facilities, the main inventories of pharmaceuticalitems are held in storage locations which are often far removed from thepatients who use them. To facilitate secure and accurate delivery of thepharmaceutical items from these storage locations to the patient, avariety of systems have been proposed and put into use. In earliersystems, referred to as a “cart exchange” system, medication carts aredistributed at nursing stations in the medical facility, remote from thecentral pharmacy, and are periodically exchanged with fully suppliedcarts. Typically these carts contain a 24 hour supply of medicationssorted by patient into specific drawers. The “used” cart is returned toa central pharmacy of supply area where the next 24 hours of medicationsare replenished. Narcotics, are stored in locked boxes on the floor,requiring two nurses with separate keys and a written log, formanagement.

While the cart exchange system is still in use for some medications,shorter hospital stays mean that the majority of patients are morecritically ill, resulting in a changing regimen of medicationsthroughout the day. This results in many new orders needing to bebrought up from the central pharmacy during the day, and a large amountof unused medication being returned. The re-stocking of thesemedications needs to be done accurately, and is very time consuming. Asa result there has been an increasing use of automated, processor based,cabinets on the nursing floors. The processor on each cabinet monitorsthe access to the pharmaceutical items in these fixed cabinets, allowingthe current on hand inventory and the need for replenishment to becommunicated to a central processor at the central pharmacy location.These processor based dispensing cabinets were initially used for themore convenient management of narcotics, and for the ability to have a“floor stock” of common medications from which a nurse could issue thefirst dose of a needed new prescription, while waiting for the 24 hourssupply to come up from pharmacy in the exchange cart, or on a specialorder basis.

Over the last eight years or so, these processor based cabinets haveexpanded to offering the possibility of storing the majority ofmedications that the patients on the floor might need during the day andnight. These medications are stored in pockets within locked drawers. Inother words stocks of medications are maintained at a desired par levelin non-patient specific form. This is referred to as “Floor Stock”. Anurse, upon entering their own personal ID, and the ID of a specificpatient, will see the medications that are approved overall for thatselected patient, referred to as “The Patient Profile”, and in somesystems, will also see what medications are due at that particular time,referred to generally as “Due Medications”. The task for the centralpharmacy, then, moves from selecting and filling exchange carts with a24 hour supply of medications to each patient, to using the centralprocessor to monitor the on-hand stock of the medications stored in thecabinets, and restocking those levels at regular intervals. A bigadvantage of this process is not having unused doses of medicationsreturned to the central pharmacy. It also means that first doses (aswell as subsequent doses) are immediately available.

In the final analysis, a mixture of the two systems is needed. There arestill many situations that continue to require medications to be broughtfrom central pharmacy For example, to avoid medication errors,intravenous fluids (IVs) that contain medication are now increasinglybeing mixed in the pharmacy and brought up to the floor for safetyreasons, rather than being prepared by nurses by attaching a so-calledpiggy-back back medication bag, to a standard diluent bag. There arealso specialized, or infrequently used medications, or those with shortlife, or requiring refrigeration, or that need special handling from thepharmacy. Finally there is the consideration of the time it may takenursing to select unit doses of medication at regular intervals throughthe day, rather than taking from a small collection of medicationspre-selected by the pharmacy for a specific patient.

In addition these cabinets have provided a variety of means to onlyallow qualified users to have access to the cabinet, and to restrict theaccess of qualified users only to items to which that particular user ispermitted to have access, or at least to track if users are accessingareas that are not required for the particular patient.

These cabinets also provide means to guide the user to the rightpharmaceutical that is being requested, either by an indicator, which isusually a light adjacent to the pocket, or by pre-opening a lockeddrawer and a locked lid, the sprung lid indicating which pocket themedication of interest is in. These cabinets also provide a record ofthe access to that particular pharmaceutical, where that access can bedetected (as is the case with the lifting of a lid that has a sensorattached).

The ideal system would only allow the user access to the single specificdose of medication requested. This is for two reasons. To ensure thatonly that medication is taken, as for example in the case of narcotics,where an addicted user might wish to divert extra doses for their ownuse. The second reason is for patient safety, to ensure that the rightmedication is selected. However for reasons of cost, manufacturers haveprovided a variety of drawers, each with different levels ofrestriction, and the choice is ultimately a trade off between cost, andaccuracy and security.

As discussed, the ideal system would allow the user only to access thesingle specific dose of medication requested. In some systems, this hasbeen provided by having metered drawers. These are drawers that havemultiple doses of the same medication, but which open just enough toreveal the one, or “N” doses, requested and no more. Other systems haveprovided a dispenser, much like a candy or cigarette machine, thatdispenses the requested medication using a rotating coil or a solenoidoperated cassette, to drop just that medication into a tray that isaccessible to the user's hand. A third method uses individually lockingdrawers, housing pockets with locked lids, each pocket containing just asingle dose of a medication. These mechanisms are currently costprohibitive for lower cost, lower security medications.

The next level of security is to use individually locking drawers,housing pockets with locked lids, each pocket containing multiple dosesof a single type and dose of a medication. In accessing these medicationdoses, the other pockets remain locked, so the nurse is not able to takethe wrong medication. They may however take the wrong quantity of theselected medication, either in error or, in the case of narcotics, fortheir own use. Various software systems have been provided to track theusers' access and steps as much as possible, in order to track patternsof use that might indicate either erroneous access, resulting in theuser taking the wrong medication, or deliberate diversion ofmedications. These software techniques often involve additional stepsfor the user. In the case of this locked pocket with multiple doses ofthe same medication, these software steps may include requiring that asecond user be found, to act as a witness, and/or counting back thenumber of remaining doses in that multi-dose pocket. In the case of“count-back”, if a user finds an error—for example the quantity in thepocket is less than the processor thinks is in the pocket, which wouldbe the number entered by the previous user in counting back—then, eitherthe current user or the previous user has either made a mistake, or hasintentionally diverted one or more doses. The problem with this approachis that taking the medication is not prevented, and analysis of theerror is done later on, usually at the end of the nurses' shift, afterthe fact, and does not point to the specific single culprit who made anerror or deliberately diverted. It requires tracking down the twoparties concerned, and having at least one of them feel “wronglyaccused”, and never having specific evidence. All these steps increasethe time take to take the medication accurately and securely.

Another type of individually locking drawer uses multiple doses of thesame medication in pockets with lids, but without locks, in order toreduce cost. The processor will monitor if a user accesses a pocket withmedications that were not selected for the patient, and will record thisas an incorrect access in an audit trail. But this is less desirablethan a locked lid, since the access is not prevented, but entered intoan audit trail in the processor, requiring someone to review the audittrail after the fact, find the culprit and discuss why they made thataccess, and ask if they took anything they shouldn't. A countbackprocess can also be added with its advantages and disadvantages. It canbe understood why it is preferable to prevent access in the first place.

Another type of locking drawer, referred to as a “Matrix Drawer”, opensto reveal a “matrix” of open pockets, each pocket with multiplequantities of a single medication. While the individual drawer may belocked, the security and safety issue in this case is the fact thatthere is no mechanism to prevent access to medications that have notbeen preselected in the processor for the patient, leaving open thepossibility for the nurse user to take the wrong medication in error, orto take additional medications undetected.

A focus in the last five years has been the desire to use bar codechecking at the point of administration at the bedside of the patient,to avoid administering the wrong medication to the wrong patient. Tothis end, unit doses of medication are all being bar-coded, either bythe manufacturer or by the central pharmacy in packaging machine, if themedication has been bought in bulk. In some cases, checks that haveevolved at the dispensing cabinets, are more appropriately done at thebedside. With the desire to have the majority of medications availablein a cabinet at the nursing station, and with the increased focus onpatient safety, it is the purpose of the inventions presented here, tomake the cabinets more cost effective and to increase the accuracy ofthe dispensing process.

While the current systems provide working methods for securely issuingmedications it would be desirable to reducing the potential cost of thecabinet drawers, allowing more items to be kept in more secure singledose dispensing mechanisms or single dose drawers, or that at least havemore items be kept in locked and/or lidded containers, so that theprocessor knows that the user is accessing the correct location. Inaddition it would be desirable to provide mechanisms to provide betterdetection of, and deterrence from, diversion in drawers that allowaccess to multiple pockets and/or multiple doses. It would also bedesirable to ensure, particularly in the case of pockets without lockinglids, that the nurse is accessing the right medication, and notaccessing the wrong pocket either deliberately or inadvertently, and istaking the right quantity of those medications, and to provide means toconfirm to the nurse that they are taking the right medication withoutintroducing additional steps.

In addition to the safety aspect of taking the right medication, thereis also the security aspect of ensuring that the wrong medication is notdeliberately taken. In many cases, the users are having to obtainnarcotic items, and the pharmacy and nursing department have seriousobligations to prevent diversion. It is much preferred to preventdiversion, either by having more unit doses of medication in lockedpockets, or by having better deterrents to diversion. Some of this canbe achieved by lowering the cost of the cabinet and so being able tocost effectively keep more narcotic items in single dose, lockedpockets. But it is also desirable to have improved mechanisms andmethods to record and know after the fact, what each user did at thecabinet, both to record who the user really was, in case they are usinga stolen identification, and to observe and record their actions inaccessing medications in the drawers themselves, and also to inform theusers that their actions are being recorded on video for example, as adeterrent to them attempting to divert.

Finally, with the increasing deployment of these systems, theiravailability has become mission critical and it is highly desirable toincrease the systems ability to aid the nurse in the dispensing processif there are any problems or questions, and to reduce the MTTR (meantime to repair) in the event of a failure.

SUMMARY OF THE INVENTION

The invention describes improved methods and mechanisms for providingsecure access to pharmaceutical and supply items in a clinical setting.In one version of the invention, a dispensing unit has an interiorhousing one or more drawers. Each drawer has one or more storagelocations, referred to as pockets. The fronts of the drawers are coveredwith one or more locking doors, preventing access to a particulardrawer, unless the covering door is unlocked. Indicators are mounted onthe side of the enclosure, to guide the user to a drawer covered by anassociated unlocked door. The unit further includes indicators on thesides of the drawers, to guide the user to the right storage receptaclesor pockets within the drawer. Some pockets may have lids. Some of thelids may have locks. Sensors associated with at least some of theindividual pocket lids may be provided to detect the lifting of a lid.Means to automatically detect the entry of a hand or fingers into apocket may be provided. There may also be locked modular drawers thatare not covered by doors, whose purpose is to issue doses one at a time,and which will only open to reveal a single dose to be taken. One ormore loudspeakers may be mounted on the unit, to provide auditoryguidance and confirmation of correct access, by sounds and voiceprompts. One or more video cameras may be mounted on the unit. Aprocessor is mounted in the unit, or, in the case of an auxiliary unit,the auxiliary unit is connected to the processor on the main unit. Theprocessor is connected to receive signals from sensors in the dispensingunit, from the video camera, and to send signals to the indicators, andto send auditory information to loudspeakers which are designed to focusthe sound specifically to the user.

In an exemplary embodiment, a user enters their identification into theprocessor, which may be done at a keyboard, or at a touch screen, orutilizing a biometric identification system such as a finger-printreader. The processor has a data base that knows whether the user isauthorized to access the cabinet or not. The user then selects a patientfrom a list of patients that is updated periodically from a mainprocessor that retains the census of patients from the hospital, andwhich is stored in the local processor on the cabinet. Or the user mayenter the identification number of a new patient not yet in the system,or set up a new patient with a temporary identification number for theinterim time until the patient data is acquired by the processor, or theuser may enter “Floor Stock” or some location identification that allowsitems to be withdrawn or added that are not associated with a specificpatient, and that withdrawal or addition can be associated with theaccount for that location. In some cases the user may be a personassigned to restock the system and may be adding, not withdrawing items,or may be a nurse returning an item that has been refused by a patientor was taken in error. The user now selects the medications andquantities of each medication that they wish to take or return for apatient, for Floor Stock or for the restock process.

The processor maintains a database with the list of medications or classgroups of medications to which the user has access. The processor alsoknows the location of those medications in the cabinet and so also knowswhich locked doors may be unlocked for that user, and which doors mustremains locked because it would give the user access to medications forwhich they are not authorized. The user selects one or more medicationsthey wish to take, and the quantities of each. As they select eachmedication and the associated quantity, if access is allowed, they canproceed to the next medication. If not they will be told they have noaccess to that medication, but that they can proceed to select the nextmedication. When the selection list is complete, the user indicatescompletion to the processor, and the processor will activate theindicators to the first door, drawer and row/column indictor for thepocket for the first medication. The user opens the door, withdraws thedrawer, identifies the pocket, and takes the medication, re-closing thedrawer. The processor senses at a minimum the opening and closing of thedrawer and will then activate the indicators for the next medication andthe process is repeated until all the medications are taken.

It is necessary to guide the user to the right pocket or pocket. Theexemplary method present here activates an indicator near the door thatis unlocked and needs to be opened, and activates an indicator in theside of the cabinet indicating which drawer to access. These indicatorsmay be one and the same. Within the drawer an indicator is activatedfrom all array of indicators at the side of the drawer to identify whichrow contains the pocket, which contains the pharmaceutical or medicalsupply items that the user has requested to remove. Simultaneously anindicator within the inside of the front of the drawer is activated froman array of indicators on the inside of the front of the drawer, toidentify which column contains the pocket, containing the pharmaceuticalor medical supply items that the user has requested to remove. In thisway the user can identify the single unique pocket at the intersectionof the row and column, and can remove the requested item. To assist inthe row identification, a second array of indicators can be placed atthe opposite side of the drawer, one of which will be activated, to nowidentify both ends of the row that has the pocket containing thepharmaceutical or medical supply items that the user has requested toremove.

In some drawers there will be lids that are locked and it will benecessary for the processor to unlock these lids. In some drawers thereare lids that are sensed by the processor when they are lifted, and theprocessor will note if the correct lid is lifted and record thatinformation. The program will also alert the user, if an incorrect lidis lifted, and record that error. The alert can be a simple sound ortext to speech or a pre-recorded message. Still other pockets may beopen, without lids, and all pockets will be revealed when the drawer isopened, but each pocket may have an individual sensor that can detectwhen a hand or the fingers of a hand, enter that pocket, to take amedication. In all these cases, the processor has positive confirmationthat a pocket has at least been accessed, even though it cannot becertain, in the case of multiple doses of the same medication in onepocket, how many items have actually been removed. In the case wherethere is just an open pocket and no sensor, the processor may only knowthat the pocket has been accessed by the opening and subsequent closingof the drawer and/or the entry of a confirmation by the user into theprocessor keyboard or touch screen, that the medication has been taken.

In another exemplary embodiment, in the case where the pockets aresymmetrically arrayed in rows and columns, there is a locking mechanismfor each individual pocket. There is an array of release mechanismsacross the width of the inside of the drawer, each release mechanismable to lock or unlock all the lids in the row associated with thatrelease mechanism. In addition there is an array of release mechanismsfrom front to back of the drawer, each release mechanism able to lock orunlock all the lids in the column associated with that releasemechanism. With all release mechanism in locked position all pockets arelocked. Activating one release mechanism into its release positionacross the width of the drawer, and one release mechanism into itsrelease position from front to back, will unlock a single lid at theintersection of that row and column of those release mechanisms.

In an another exemplary embodiment, the sensors on an individual pocketsend a signal that a pocket has been accessed. A mechanism for detectingthe opening of lids of pockets containing pharmaceutical or medicalsupply items in a drawer is described in the case where the pockets aresymmetrically arrayed in rows and columns. The lids are provided witharms extending into the body of the drawer, the end of the arm formedinto a tab. An array of light sources are placed on the interior of oneside of the drawer and corresponding light detectors are arrayed on theinterior of the other side of the drawer, at least some of thelight/detector pairs positioned so that the movement of a lid andassociated tab as the lid is lifted, will break the beam of lightbetween the source and receiver. It is preferable that the light sourcebe infra-red to avoid interference from visible light. Similarly, anarray of light sources is provided on the interior of the front side ofthe drawer and a corresponding set of light detectors is arrayed on theinterior of the back side of the drawer, at least some of theselight/detector pairs being positioned so that the movement of a lid andassociated tab as the lid is lifted will break the beam of light betweento source and receiver. In this way, the lifting of a specific lid willbreak in source-receiver pair in the cross direction, and onesource-receiver pair in the front to back direction, allowing theprocessor to identify the single pocket at the X-Y intersection of thatrow and column.

In another exemplary embodiment there are modular locking drawers in theenclosure. These drawers are designed to contain unit doses ofmedications that are dispensed one at a time. The drawers are designedso that to advance to a second medication the drawer must be returned toit's fully closed position for each take. If, of course, a subsequentdose is not authorized to be taken, then the drawer is relocked. Whenthe drawer is restocked there is a reset mechanism, that is operated bythe restock technician, to reset this sequencing mechanism to the firstfull pocket.

In a further exemplary embodiment, a video camera is placed at the topof the cabinet pointing downward and another is placed in the center ofthe cabinet facing the user. When the user logs in, either using theprocessor keyboard or using one of many biometric identification devicesthat may be placed on the cabinet and connected to the processor, aprocess of video recording begins, recording both the face of the userand, utilizing the downward facing camera, any activity that the usermay undertake as they withdraw medications from pockets in withdrawndrawers. At the completion of the user session, the video recordings areattached to the transaction record for that user in that session, andare stored in the processor.

This method for detecting access to a pocket does not work if there isno lid, so another method is described. A pair of metal plates in thewall of each individual pocket, form a capacitor. The change indielectric and associated capacitance when a hand or the fingers of ahand enter the pocket, is detected using a sensitive bridge circuit.This bridge circuit is self balancing over time to accommodate the factthat the capacitance also varies due to the increase or decrease indielectric constant in the gap between the capacitor plates created bythe varying contents of the pocket itself. Since the circuit isprimarily looking for an increase in dielectric when fingers areinserted, the bridge balancing circuit balances out decreases incapacitance rapidly, but remains sensitive to increases in capacitance.The detection of the dielectric change only occurs when the processorhas recorded that a user has logged into the processor and that themedication retrieval process is not finished. In this way extraneouschanges are ignored.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a dispensing unit having a processor, controlinterface, speakers, video cameras, and a number of non-locked drawerscontaining pockets, with guiding indicators. The drawers are covered bylockable doors. There is also a storage compartment covered with alockable door over it. There are also modular, locked drawers notcovered by doors

FIG. 2 illustrates the same cabinet viewed from the front.

FIG. 3. illustrates an auxiliary dispensing unit which is the same unitas in FIGS. 1 and 2, but without a processor interface and with anadditional storage compartment.

FIG. 4 illustrates the dispensing unit of FIG. 3 with the dual-lockableservice sections withdrawn from the cabinet to reveal the circuit boardsand flex cable connections.

FIG. 5 illustrates the top view of a typical drawer, showing theindicators arrayed along the edges of the drawer, which are used toguide the user to the correct pocket by indicating the row and columncontaining the pocket of interest.

FIG. 6 illustrates a mechanism for indicating the correct pocket usingplastic light pipes that are built into the top of the dividers of thecompartment.

FIG. 7 shows the top of a drawer that utilizes the light pipes showinghow the pocket of interest to the user, is highlighted on all four sidesby the light pipes.

FIG. 8 is a perspective, angled view, drawing showing a mechanism andmethod for detecting the opening of a lid using lights and photodetectors arrayed in the X and Y row and column coordinate directions.

FIG. 9 is a side view, perspective drawing showing a mechanism andmethod for detecting the opening of a lid using lights and photodetectors arrayed in the X and Y row and column coordinate directions

FIG. 10 is another side view, perspective drawing showing the mechanismand method of FIG. 8 for detecting the opening of a lid using lights andphoto detectors arrayed in the X and Y row and column coordinatedirections, with an extension that is angled back, allowing the lid toopen beyond vertical.

FIG. 11 is an angled view, perspective drawing showing a mechanism andmethod for locking one or more lids on pockets in a drawer, using anextension from the lid with a tab on it, interacting with bars in the Xand Y coordinate directions, with appropriate slots cut in the bars, thebars being rotated at one end by rotary solenoids, and supported at theother end by rotary bearings.

FIG. 12 is a side view, perspective drawing showing the mechanism andmethod of FIG. 11 for locking one or more lids on pockets in a drawer,using bars in the X and Y coordinate directions, with appropriate slotscut in the bars, the bars being capable of being rotated ninety degreesat one end by rotary solenoids, and supported at the other end by rotarybearings. In this drawing the bars in the Y direction would permit thelid to open, but the bar in the X-direction prevents the opening.

FIG. 13 is similar view to FIG. 12, but in this case, the bars in the Xand the Y direction both permit the lid to open, so the lid iseffectively unlocked at the X-Y intersection point of those twoactuated, rotated bars, allowing the lid tab to move in the direction89.

FIG. 14 shows a set of open matrix pockets, one with an exemplary pairof metal liner plates that acts as a capacitance detector of thepresence of fingers entering the pocket.

FIG. 15 shows the principal elements of an analog circuit to detect thechange in capacitance of the two metal liner plates of FIG. 14

FIG. 16 shows how the signals at two of the points in the circuit ofFIG. 15 might vary over time as a medication is withdrawn from thepocket.

FIG. 17 to 19 show a flow chart of the typical work flow at the cabinetand variations on the speaker shapes which may be utilized in thecabinet, respectively.

FIG. 20 shows a closed modular locking drawer for dispensing singledoses.

FIG. 21 shows a modular drawer partially retracted to the maximumallowed by the shuttle mechanism, to reveal Pocket 1.

FIG. 22 shows the modular drawer fully-closed again

FIG. 23 shows the modular drawer now able to open to reveal both pocket1 and pocket 2

FIG. 24 shows the front of the drawer unlocked and opened to reveal theshuttle reset mechanism

FIG. 25 shows the side view and shuttle mechanism of the closed drawerof FIG. 20, with the case removed

FIG. 26 shows the side view and shuttle mechanism of FIG. 25, revealinghow the shuttle mechanism prevents the drawer from opening farther thanPocket 1

FIG. 27 shows the side view and shuttle mechanism of FIG. 25, revealinghow the stop mechanism is advanced to allow the drawer to open to Pocket2

FIG. 28 shows the side view of the drawer now opening past Pocket 1 andthe position of the shuttle mechanism as it moves to a new lockingposition

FIG. 29 shows the side view of the drawer now open to reveal pocket 2,but prevented from opening further by the new locking position of theshuttle mechanism

FIG. 30 show the side view of the drawer with the front door unlockedand the reset mechanism withdrawn

FIG. 31 shows the drawer now fully retracted with the reset mechanismwithdrawn and the shuttle mechanism positioned by this full withdrawndrawer into the reset tab at the front of the drawer

FIG. 32 shows the drawer now closed with the reset mechanism withdrawnand how the shuttle mechanism remains reset at the front of the drawer.

FIG. 33 shows the reset mechanism returned into operational position,and the drawer door closed and locked over it, leaving the drawer resetand ready for use again

DETAILED DESCRIPTION OF THE INVENTION

An exemplary dispensing unit is shown in FIG. 1. Dispensing cabinetssimilar but not identical to this drawing are common in acute carehospitals. However, the purpose of the inventions presented here is toprovide methods that allow these cabinets to provide betterfunctionality at lower cost, and to provide improved serviceability, inparticular to provide faster mean-time-to-repair (MTTR), since thesesystems need to be available twenty-four hours a day, seven days a week,year in, year out.

In FIG. 1, an enclosure 1 is shown that contains a number of functionalitems. A processor with screen 6, which is preferably a touch screen,and a keyboard with mouse pad 7 is placed at a convenient height for auser. The console area also contains a printer enclosed within thecabinet with a slot 8 for the paper to exit, and optionally an automaticidentification device, 25, which could be a magnetic card reader, a barcode reader or one of many biometric devices such is a finger print,face recognition or hand recognition device for example. A work surface5 is provided on which a user can place papers, and/or a tray ofcontainers to receive medications or other supplies taken from thecabinet. The enclosure 1 contains a number of different means forstoring items to be a dispensed. In one case, a compartment 2 is coveredby a locked door 23, with hinges 4 and a handle 3. There also may bedrawers 9 with handles 24 for opening them, and access to these drawersis controlled by locking doors 28 that selectively cover the drawers 9,the doors having hinges 26 and a locking pawl 27 that mates with a lockmechanism 29 on the cabinet.

Within the drawer there are pockets. These pockets may be open matrixpockets, or lidded pockets, and the lids may be locking or non-locking,and may, or may not, be equipped with sensors to detect when they areopened. On the side of the cabinet there are arrays of indicators 10 toguide the user as to which compartment or drawer to open. These sensorsmay be inside the door, and only revealed when the door is opened, ormay be outside the door and visible both with the door closed as well asopened, allowing the user to see which drawer is indicated during thetime they are approaching the door to open it, and in fact guiding theuser to the right door to open to access the required drawer. There arealso modular drawers 33 that are not covered by oors, whose purpose isto dispense one dose of a single medication at a time. These drawers aredesigned so that the drawer must be fully closed and opened again foreach dose taken, allowing the processor to count the doses taken. Toprovide convenient and fast access to electronics for repair, a pair oflocks 12 and 13, allow a cover 11 to be removed. Removal of the covergives access to mechanical or electronic release mechanisms concealedfrom tampering by the cover, which open other covers of the cabinet, orto release other hidden mechanisms and circuit boards from the front forservice. A pair of locks is provided so that it might be the policy ofthe hospital that two people, each with separate and different keys,would be required to access the system which may contain narcotics. Thelocks are mounted on a simple cover, so that, should a key be lost orstolen, and the security of the system compromised, it is inexpensive tore-key the system. FIG. 2 shows a front view of this cabinet of FIG. 1.

The drawers 9, of which an open one 14 is shown in FIG. 1, is shown inmore detail in FIG. 5, with multiple pockets 15. There are two arrays ofindicators 30 and 31, in FIG. 5, where the indicators are typicallights, on at least two edges and preferably a third array of indicators32 on the third edge. To indicate the pocket of interest, 16 from whichthe medication should be taken in this illustrative example, the “X” and“Y” coordinates of the pocket are shown by indicators 19 (the “X”coordinate) and 18 (the “Y” coordinate). The X-Y pattern made by thepockets themselves allows the user's eye to easily see at which pocket,16, the X-Y lines from these coordinate indicators meet. This canfurther be enhanced by providing a second “Y” coordinated indicator 17on the other side of the drawer. Since the drawer is not always fullyretracted, it is not useful to provide a second “X” coordinate indicatoron the back side of the drawer opposite to 19, since that indicatorwould be concealed until the drawer was fully open, and in many cases itmay not be necessary to fully open the drawer to access the desiredpocket. However, a second “X” indicator could be provided by placingthat indicator on the cabinet frame just above the drawer.

For an eight by eight pocket array, there are sixty-four pockets and ifan indicator is provided adjacent each pocket it would requiresixty-four indicators whereas, the method and mechanism shown hererequires sixteen indicators—or a maximum of twenty-four indicators, ifthe option to have indicators on both sides of the drawer is chosen.This means less cost. In addition, since the indicators are on the sideof the drawer, this allows the possibility to have a standard (dense)array of indicators on the drawer and the drawer to be convenientlyre-configured by inserting a new pocket liner in the standard drawer,with a different array of pockets. By entering the new configurationinto the processor, the right selection of indicators will be used fromthe dense array, to line up with the pocket arrangement for the newliner. In this manner, just one drawer might be provided, with standardelectronics for the indicators, reducing the cost for manufacture, andallowing the hospital to re-configure systems just by replacing theinsert in a drawer, not having to replace the whole drawer mechanism.

In most cases however, the user needs access to all drawers, or, if auser is restricted, it is usually to a broad class such as narcotics,that can be kept in one group of drawers. Lower costs are also achievedby having just locking doors 28, over inexpensive molded plastic drawers9. Although certain users may need to be restricted from accessingcertain medications, this is usually to a broad class or group ofmedications like narcotics.

The camera 20 in FIGS. 1 and 2, should be able to record the actionsfrom a vertical position, unless the user is deliberately trying toconceal their actions. If the pockets have access detection mechanisms,through lid sensors or, in the case of open pocket matrix drawers,sensors that detect the presence of fingers entering the pocket, thenthe speakers 22 on the cabinet in use, can optionally state the name anddose of the medication being accessed to confirm that the user is takingthe right medication. This speech can either be text-to-speech, but willpreferably be a sound file recorded by the pharmacist with correct andaccurate pronunciation, recorded when the pharmacist enters themedication initially into the data base.

A typical user process is shown in FIG. 17, and the followingdescription will refer to the steps depicted in FIG. 17 as well as referto the physical components depicted in FIG. 1. A user approaches thecabinet and enters their identification in step 160 of FIG. 17 on thekeyboard 7 of FIG. 1, or using an automatic entry device 25. Theprocessor may optionally ask for the entry of a user password on thescreen 6, to be entered on the keyboard 7. At this point the processorwill know the unique identification of the user. In step 161, theprocessor will begin recording the user and their actions on videocameras 21 and 20. Video recording will not necessarily be at the full30 frames per second, but will more typically be at a lower speed toconserve memory, possibly 5 frames per second or less. It will also bepreferable to record at a lower resolution, say 320 by 240 pixels and touse an effective compression technique such as MPEG-4. The processor,knowing the user ID, now knows the user, and so to which medications theuser is allowed access, and will only open doors for those appropriatedrawers or compartments.

In step 162, the user may now select a patient from a list held withinthe processor, or enter a new or temporary patient ID or select “FloorStock” in the case where a medication is to be taken for future use, orselect “Remove Inventory” if the medication is being moved to analternate secure location, or select “restock” if they are addinginventory to the cabinet. In step 163, the user will pre-select one ormore medications they wish to remove, entering the quantity of each andreading any alert information provided by the system, whether it bepatient specific, such as allergy alerts, or medication specific, suchas route of administration. At this stage the user may also be asked toenter information, such as the reason for the dispense or return of themedication. The processor will also know, at step 164, whether the useris allowed access to each medication selected. If not, the processorwill alert the user to that effect, but will allow the user to continueto select other medications to which the user maybe does have permissionto access.

When the user has selected all the medications they wish to, and areallowed to, take, they indicate on the screen in step 165 that they nowwish to take these preselected medications. The processor in step 166will unlock the door 28, covering the drawer 9, containing the firstmedication that has been selected. In step 167 the processor indicateswhich door, 28, is unlocked by activating the appropriate indicator 10,and in step 168 indicates which drawer to withdraw from the cabinet. Inthis case the indicator 10 fulfills both purposes. In step 169 the user,having opened the unlocked door, opens the drawer, and in step 170 theY-row, 13 and 17, and X-column 19 containing the pocket are indicated.If the pocket has a locking lid then that lid will be unlocked in step171, and if a lid is present the user lifts the lid in step 172 andtakes the medication. If the system detects access to the pocket, eitherby sensing the lifting of the lid or by sensing the presence of theusers fingers in the pocket, then in step 175 a voice prompt isautomatically played, using the sound file stored in the processor orusing text to speech, reciting the name and dose of the medication.Additional information can also be included in the voice promptincluding patient information such as allergy warning, and medicationspecific information such as route of delivery, or the need for awitness, and other useful information. If access to the medication isnot automatically sensed, then the user needs to return to the screen instep 174 to indicate the medication has been taken, which then triggersthe voice prompts and associated displays.

In step 176, if a countback is needed, the user can be prompted both byvoice and on the screen, including reciting the current quantity theprocessor believes is in the pocket. When countback is completed, instep 177 the processor repeats the dispense process for the nextmedication, or, if this is the last medication selected, will prompt theuser in step 178 to close all drawers and doors, and at this point anylocking lids that have been opened will lock, and closed doors will belocked, step 179. Video recording will cease in step 180 and a record ofthe whole transaction sequence together with the video file will bestored in the local processor and also sent, as a periodic update to thecentral server. It is preferable that doors 28 are spring loaded so thatif the doors are opened beyond ninety degrees, they stay open, but ifthey are returned to any position less than 90 degrees open, the doorwill swing shut, and that process will initiate re-latching and lockingof the door. It would be unusual for a care-giver to not shut drawersand doors, since they are acutely aware of the importance of keepingmedications secure, but if that were to happen, then, after a shortperiod, the cabinet should give voice prompts that the doors and drawersneed to be shut. Those prompts should be given until that action iscomplete. A short waiting period is desirable, to give time for a normaluser to complete the task of closing the doors without being bothered bya prompt to take an action they know must be performed. In general,voice prompts should be brief, and preferably tailored to the user togive essential safety information, but not to annoy.

FIG. 6 shows an alternate way to provide the less expensive “X-Y”coordinate indication of the pocket of interest 16, using indicatorsthat are not adjacent to the pocket. This would typically be used inso-called “matrix” drawers that have no lids. In this case the lightfrom a relevant pair of indicators on the side of the drawers, 40 and41, are sent down light pipes 44 and 45, arrayed across the width of theliner in the drawer, to indicate the “Y” axis coordinate. Similarly apair of indicator lights, 42 and 43, on the front or back side of thedrawer send light down light pipes 46 and 47, arrayed from front to backin the liner in the drawer, to indicate the “X” axis coordinate. Theliner containing these light pipes could be a single molding, or couldbe intersecting pieces that could be assembled to make a matrix ofpockets. Regardless, the effect is to illuminate the “X-Y” lines to helpguide the user's eyes to the pocket of interest, 16, at the intersectionof the X-Y coordinates. The indicator lights are still on the side, butwhen light is passed down a light pipe, while much of the light istotally internally reflected, various additives in the plastic can causethe whole pipe to also glow, providing the appearance of a lit lineacross the drawer. This is illustrated more specifically in FIG. 7,which is a top, or plan view of the drawer, which clearly shows how thelines created by the light pipe indicate that pocket 16 is at theintersection.

An important aspect of a dispensing system is accuracy. While apreferred method that has been described in the past is to only provideaccess to a single type of medication by placing each type in lockedpockets and only opening the lid of the right pocket, this method isexpensive. The invention proposed here, involves detecting when a pocketis accessed and providing a voice prompt which states the name and dosequantity of the medication being accessed. The voice prompt could beprovided by a text-to-speech process, but, because of the risk ofmispronunciation of hard to pronounce drug names by text-to-speechsoftware, it would preferably be a sound file of the recorded voice ofthe pharmacist, made when the medication was originally entered into thedatabase. The sound file would be transmitted along with all the otherdug information needed, to each dispensing cabinet processor and becomea part of the data base. Text-to-speech would be used in an emergency ifthe sound file was corrupted or missing. An important aspect is theability for the user to clearly hear the spoken description of themedication, while not making the sound so loud that it disturbs otherworkers or patients. To this end the speaker 22, or speakers 22 and 24,shown in FIGS. 1, 2 and 3, are placed at the height of the average userand are pointed in the direction of their ears. Because users may alsobe bending down to take medications, additional speakers low in thecabinet are recommended. This allows minimum volume with maximumpossibility for the user to clearly hear. Triggering of the sound fileis either from the lifting of a lid or from a capacitance bridge circuitthat detects the presence of the fingers in a particular pocket. It isalso desirable that the speakers focus the sound, rather than disperseit. To that end a concave parabolic horn shape is recommended as show inFIG. 18, 190 is the speaker magnet and the sound waves emanating fromthe central cone 193 are reflected off the concave parabolic surface191, causing the sound waves to travel in parallel, focusing them at theuser rather than spreading out to others. This is in contrast to atypical medium to high frequency speaker shown in FIG. 19 where there isa convex horn 196 causing the sound 197 from the cone 198 to spread outover a large area, which is normally the kind of propagation that isdesired. In this case it is desirable to keep the sound focused and thearrangement of FIG. 18 has advantages in this area.

Various mechanisms have been described in prior art for detecting thelifting of a lid using an adjacent sensor which is typically an opticaltransmitter and detector adjacent a move arm attached to the lid of thepocket, or is a magnet that attached to the moving arm attached to thepocket lid that triggers a hall effect device. For accuracy ofdispensing it would also be desirable to detect when a persons fingersentered the opening of a non-lidded matrix pocket, allowing the voiceprompt to recite the name and dose of the medication from the sound filepreviously stored in the database, or using text-to-speech from thecharacter information stored in the database. FIG. 14 shows a mechanismand method for accomplishing this. A matrix draw consists of openpockets defined by Y-direction dividers 102, 103, 104 and X-directiondividers 105, 106, 107, 108. In this example we are focusing on a pocket109, defined by dividers 103, 104, 105 and 106. In the walls of thedividers of each of the pockets are two metal plates 110, and 111designed to surround the inside of each pocket and covered with aninsulator. The plates that meet, but do not quite touch at points 113and 114. These two plates form a small capacitor whose impedance isaffected by the dielectric between and in the vicinity of the plates.The dielectric constant, and hence the capacitance will increase as aperson's fingers are inserted into the pocket to remove a medication.This will be a very small capacitance increase and so a sensitive bridgecircuit is needed to detect the change.

FIG. 15 shows an example of a suitable bridge circuit. The AC voltageproduced at point 132 from the high frequency, low impedance AC source134, is a function of the fixed capacitor 122 and the capacitor formedby plates 110 and 111 which has a variable impedance. To balance thebridge and make the voltage at 135 equal to 132, the effective positionof a slider 135 on a rheostat 136 is adjusted. In practice, there willbe no physical rheostat, but a circuit 131 that performs that functionof variable resistance, that is controlled by the input level 130, 123is a high gain operational amplifier, so any sudden increase or decreasein capacitance of the capacitor formed by 110 and 111, will cause asmall change to the input of 132 causing a large change in output,either draining the storage capacitor 129 or increasing it's voltagesthrough the resistor-diode combination 127/128 and/or the resistor 126.The resistor 127 is smaller than the resistor 126 and in combinationwith the diode 128, creates a SDFS (slow-depart-fast-return) effect onthe capacitor 129 voltage at 137, whose purpose will be explained in thenext Figure. Voltage changes occur slowly on line 130, and this meansthat the circuit is always slowly balancing itself through the voltageadjuster 131, such that the capacitor voltage 137 is zero and the bridgeis in balance. This is important since the capacitance of 110/111 willchange with pocket content and other conditions, so it important thatthe circuit is constantly adjusting for these gradual changes over time(typically about 5 seconds).

The system will start looking for changes when the user has logged in,has selected the medications and has opened the door covering thedrawers to begin accessing medications. Since the system is guiding theuser to the right location, the system knows which pocket they should beaccessing. There are three sources of sudden change in capacitance. Oneis when the drawer is opened. In this case the bottom of the drawerabove, and it's associated contents, are suddenly no longer above110/111, causing a sudden drop in dielectric in the area above thecapacitor formed by 110/111, and we wish to ignore this change.Insertion of fingers into the pocket causes a sudden increase incapacitance and we want to detect this and trigger the voice signal torecite the sound file and confirm the name and dose of the medication.Withdrawal of the fingers, probably accompanied by a medication grippedbetween those fingers, causes a drop in dielectric and hence a drop incapacitance, which we also want to ignore. Returning the drawer to theclosed position causes an increase in capacitance, but by this time thesystem knows that the cycle is complete and will ignore the signal fromthat pocket caused by the drawer closing.

The signals received are shown in FIG. 16. The impedance of thecapacitor with the drawer closed is shown in the top chart in FIG. 16,and the signal 133 at the output of the op-amp, 123, is shown in thebottom chart in FIG. 16. As time progresses the drawer is withdrawn atpoint in time 144 causing a drop in capacitance at 140 with anaccompanied unbalancing of the bridge voltage, and hence the output 133of the op-amp shown in the chart at 145. But due to the SDFR circuit thesignal 133 quickly drops back to zero at 146. This signal is negativegoing, and so is not considered to be a “take” event. When the hand isinserted at 141 the capacitance increases and this is registered as apositive 133 signal, shown just after point 147 and only slowly decays,148, and so is registered as a “take” and will trigger the voice promptfor the medication in that pocket to be played. At time 150 the fingersand medication are removed from the pocket, causing a sudden drop incapacitance. Again this drop causes a negative change which decaysrapidly and is not considered a “take”, since it is negative going.

At 151 the transaction is considered completed since a “take” in thatpocket has been seen, and subsequent signals are ignored as the drawercloses. So, for example, as the drawer closes and the increaseddielectric above increases the capacitance and impedance, 143, theassociated increases in voltage 152 is ignored. In practice, theelectronics of FIG. 15 would be more complex, including theimplementation of the variable resistor circuit 131, but this couldeasily be accomplished by someone skilled in the art. While the bridgebalance circuit of FIG. 15 is shown as an analog circuit, the logicperformed in FIG. 15 could also be implemented using a microcomputerwith the input signals converted to digital form, or by some combinationof an analog and digital circuit.

FIG. 8 illustrates a method and mechanism for utilizing light detectorsarrayed in an X-Y direction, to detect when the lid on an individualpocket is lifted. For simplicity only a single pocket 54 is shown with alid, 51 and associated extension arm 53, with forward tab 68 and angledtab 69. A top through which the opening of each pocket would appear, andon which each closed lid would rest, is not shown, but this top andassociated openings for each pocket would be in a horizontal plane levelwith the top of the pocket 54. There would be a small slot through whichthe extension arm 53, and other extension arms for each lid, wouldproject down into the interior of the drawer. The side view of FIG. 9more clearly illustrates the tab arrangement on the extension arm 53.Referring back to FIG. 8, 59 is a light source, preferably infra-red,and there would be many arrayed along the side 64 of the drawer, 60 is acorresponding detector on the opposite side, again part of a symmetricalarray of detectors opposite the lights on 64. Similarly in the Ydirection, light source 59 is part of an array of lights on the insidefront of the draw sending a focused beam of light to correspondingdetectors 57 on the back side of the drawer, part of an array ofdetectors along the back side 65.

With the lid 51 in closed position the light beams 61 and 67 are notinterrupted, and this would be true for each pocket lid and X-Ylight/detector pair combination in the drawer. However when the lid 51starts to be opened, when it reaches position 55, shown by the dottedoutline, the extension arm 53 has moved to a new position 56, and thetab 68 interrupts the light beam 61, and the tab 69 interrupts the lightbeam 67. Hence the light beams in the X and the Y direction, for justthat position, are both interrupted, indicating that the lid has beenlifted. No indication is given as to whether the lid is being opened orclosed, but our interest is only in knowing at that time if the pocketis being accessed. The light interruption need not necessarily besimultaneous, but the electronics should be set up to such that, givensay the X coordinate beam is interrupted first, a corresponding signalfrom a Y coordinate detector is received within a short period of time,which would be well under a second.

FIG. 10 shows an improved version where the tab 53 is angled backward.This allows two things. Firstly, the breaking of the light beams by theextension arm 53 occurs when it is at the lowest position, 63, of thearc around the pivot point 52. This allows the pockets 54 to be thedeepest without themselves interfering with the light beam. Secondly,when the lid is fully open in position 95 and arm 53 is stopped by theunderside of the drawer top in position 96, which is level with the topsof the pockets, the weight of the lid 95 will hold the lid open, sincethe lid is heavier than the extension arm. This is desirable whenneeding to get fingers into a small pocket to take out a singlemedication from many.

FIG. 11 shows a mechanism and method for locking lids using an array ofbars, arrayed in the X direction exemplified by 98 and 99, and the Ydirection exemplified by 74, 75, which have appropriate notches in theseexamples 79, 80, 81, 82 and 83, 84, 85, 86 in the bars. The bars arerotated by solenoids, for example solenoid 77 for bar 99, and supportedat the far end by rotary bearings 78. Similar to FIG. 8, here in FIG. 11for simplicity only two pockets 54 and 70 are shown with lids, 51 and 71respectively, with associated extension arm 53 with forward tab 68 andangled tab 69, and arm 72 with similar forward tabs at 73. A topsurface, through which the opening of each pocket would appear, and onwhich each closed lid would rest, is not shown here to allow theinternal workings to be seen. However, such a top surface, and theassociated openings for each pocket, would be in a horizontal planelevel with the top of the pockets 54 and 70. There would be a small slotthrough which the extensions arms 53 and 72, and other extension armsfor each lid, would project down into the interior of the drawer.

The normal locked position for a Y-direction bar is vertical as shown bybar 98, and for an X-direction bar, is flat as shown by bar 75.Consequently an extension arm (for a pocket not shown) at position 86 inFIG. 11 would be locked by both X and Y bars. In contrast, in FIG. 13,the X bar 99 has been rotated from its normally vertical position to aflat position by solenoid 77, removing the blocking edge 92, and the Ybar 74 has been rotated vertically by solenoid 90, removing the notch 80from the path of the tab 72, allowing the extension arm 53 and connectedlid 51 to rotate along the arc 89.

Both the X and Y bars must be in the “open” position for the arm to befree. For example, for pocket 70 and arm 72 in FIG. 11 and shown in moredetail in FIG. 12, even though bar 74 is vertical and so the notch 79has been removed from the way of the tab 73, the bar 98 remains in thevertical (locking position for Y-direction bars), and the corner 91blocks the tab 73 and prevents the arm 72 from rotating forward.

This methodology provides economy. For an eight by eight matrix ofpockets, you need sixteen rotary solenoids with this X-Y method,whereas, individual solenoids for each pocket would require sixty-foursolenoids.

FIG. 20 shows a modular drawer 33 that was shown in FIG. 1 and FIG. 2.The drawer in FIG. 20 is in a housing 203 that would be contained withinthe cabinet 1 of FIG. 1, the drawer sliding out from the housing 203which would remain fixed relative to the cabinet 1. The drawer is heldshut by a solenoid operated lock at the back of the drawer, which willbe described later in this document. There is also a drawer closuredetector 201. The key lock 209 shown at the front, is for the purpose ofrestocking the drawer, and its use will also be described later in thisdocument. In FIG. 21, when the drawer has been restocked and is firstused, the drawer only opens to reveal a single first pocket 213,containing a single medication. If the user has requested two of thesemedications, then the user must return the drawer to the fully closedposition 217 shown in FIG. 22, at which point the sensor 201 at the backof the drawer informs the processor that one dose has been taken, andthe act of closing the drawer fully, mechanically advances a shuttlemechanism within the drawer, such that when the drawer is opened again219, as shown in FIG. 23, the second pocket is revealed, 221 allowingthe second dose to be taken and so on. When the requested number ofdoses has been taken by opening and shutting the drawer, then on thenext complete closing of the drawer, the processor, being informed thatthe drawer has opened and closed the requisite number of times by thesensor 201, will re-latch the solenoid at the back of the drawer,preventing the user from pulling the drawer out again and taking moredoses than requested.

At some point the drawer needs to be restocked, either because it isempty or because it is the scheduled time to re-fill what has beentaken. The restock technician enters their identification into theprocessor and selects the restock function at which point the drawersand doors on the cabinet, to which the technician has access, unlock.The restocking an shuttle reset process is performed as shown in FIG.24. A key is used to unlock the lock 209 moving the latch from lockedposition 221 to open position 225 freeing it from the slot 234, allowingthe door 205 to be opened in the direction 227. A release tab 229 ispulled out and down in the direction 282, and the drawer 223, along withthe attached open front cover door 205, is pulled fully open in thedirection 233. Restocking of the pockets is then done, and if all theslots cannot be restocked, then doses are put at the back of the drawer.The drawer is then fully closed again, in the direction 235, and therelease tab 229 is returned. The door 205 is closed and the lock 209 islocked. Since this is during the restocking process the solenoid latchat the top back of the drawer is still open. So, if the drawer was notcompletely restocked, the restock technician opens and closes the drawerenough times, to move the shuttle down so that the pocket before thefirst one that actually contains a medication in, is exposed. This isthe reason that, if the drawer is not to be fully restocked, then stockis placed starting at the back, and leaving open pockets at the front.If the items were placed in the front, then at some point the drawerwould reveal empty pockets at the back to the user, and there would beno easy way to prevent that. Doing it this way, the empty pockets arecleared by the restock technician, leaving the drawer set to use for theremaining doses that are present. The restock technician, having set thedrawer up ready for dispensing the first dose available, then informsthe processor the drawer has been restocked, the drawer is locked by thesolenoid latch, and the technician moves to the next drawer.Alternatively the restock may complete all restocking, then inform theprocessor that they are finished, and then all locks will lock.

There are many ways to implement the method of requiring a drawer to beclosed in order to advance the opening position by one, accompanied by amechanism to reset the drawer after restocking. One embodiment is shownin FIGS. 25-33.

FIG. 25 shows the side view of the drawer, with the housing 203 of FIG.20 removed, exposing the advancement shuttle mechanism. The positions ofthe top side of Pocket 1 is indicated at 213, and the top side of Pocket2 at 221, and so on. These Pockets extend down into the body of hedrawer, but are just shown at the top in this drawing to indicate theirposition and avoid extra lines in the drawings. There is a serratedplate 243 attached to the side of the drawer, and spaced a smalldistance from the side of the drawer, with enough space for a smallwheeled trolley, 245, to run in a groove, 244. Extending from thetrolleys is a leaf spring 247 that holds a cylindrical shuttle 249 in adownward position against the upper edge of a lower serrated plate 261.The trolley 245, spring 247 and shuttle 249 comprise a shuttle assembly250.

The lower serrated plate, 261 slides in the plane of the side of thedraw, along grooves 265 and 259, held in position by pins 263 and 257.The serrated lower plate 261 is held to its left most position at thepoint 254, by a leaf spring 269 on the inside of the door 205 which isnormally locked by lock 209. At the back of the drawer a sensing device201 senses when the drawer has been fully closed. This sensor could bean optical sensor or a Hall effect device or a mechanical micro-switch.There is also the option to latch the drawer. A hinged pawl 271 operatesin such a way that if the drawer closes and the latch 273 is in theupward position, the pawl is shaped so that it slides over the latch andfalls into the latch socket and locks. The drawer is unlocked when thesolenoid 275 is operated, pulling the latch 273 down from the hook onthe pawl 271. There are many other electromechanical latchingarrangements available to those skilled in the art.

Initially the shuttle is in position 253 in the groove 246 between upperserrated plate 243 and the lower serrated plate 261. Referring now toFIG. 26, as the drawer is withdrawn, the front frame of the drawer 252,pushes the shuttle 249 from position 253, up to the indentation 202 onthe lower serrated plate 261. The spring 247 pushes down oil the shuttle249, but the shuttle is trapped at this point between the top serratedplate 243 and the front frame of the drawer housing 252, and the drawercannot be pulled further out. At this point, Pocket 1 at 213 is exposed,so the user call take the contents of that pocket. If the drawer is slidin and out without fully closing the drawer, the shuttle stays in thesame position and will continue to prevent the drawer from openingfurther. However if the drawer is fully closed, as shown in FIG. 27, thestop 270 attached to the lower serrated plate 261, pushes the plate 261forward relative to the side of the drawer, moving in the lowerhorizontal parts of the grooves 259 and 265, and pushing against theleaf spring 269. This opens a gap between the serrated plates at theposition 202 and the shuttle 249 is forced down by the spring 247, toposition 260. During this action the sensor 201 sends a signal to theprocessor that the drawer has been fully closed. If only one dose is tobe taken then the solenoid 275 is release and the latch 273 will catchon the pawl 271 and the drawer will lock. If however a second dose isauthorized by the processor to be taken by the user, the latch willremain unlocked, and the drawer can be opened again as show in FIG. 28.Since the pressure is off the stop 270, the spring 269 pushes the lowerslidable serrated plate 261 back into its left-most position so thatthere is no gap at the top position 202. As the drawer is withdrawn, thefront frame 252 pushes the shuttle 249, up the groove 246 created by thebottom edge of the upper serrated plate 243 and the top edge of thebottom serrated plate 261 until the shuttle 249 reaches the stopposition 202. In FIG. 29 we show the shuttle at its new stopped position202. Note that now the second pocket 221 is now exposed, but the drawercannot be opened further unless it is fully closed again.

We now address the issue of how to get the shuttle back when the draweris to be restocked with items. The drawer may not be fully empty at thetime of restocking. Referring to FIG. 30, the restock technician unlocksthe lock 209, and opens the door 205. This is also shown in FIG. 24 asdescribed before. Returning to FIG. 30, the technician then pulls thefront tab 229 of the lower serrated bar in the direction 282, which isguided by the pins 257 and 263, running in the slots 259 and 265. Thelowering of the serrated plate 261 relative to the body of the drawer inthe process of pulling tab 229 forward and down, reveals the smoothsurface of a fixed plate 262. The shuttle 249, pressed down by thespring 247 now rides on this smooth upper surface 262. In FIG. 31, thewhole drawer is pulled out to its maximum extent in the direction 292,carrying the shuttle and everything with it. At some point, dependingwhere the shuttle was when the restock technician started the process,the shuttle will ride up over a catch 255 attached to the drawer frame252, and the shuttle will cease to move forward. As the drawer is thencompletely withdrawn, the shuttle trolley 245 will be driven to the backof the moving drawer, the shuttle itself staying caught in the notchcreated by 255 and the stationary front frame 252. Eventually the draweris prevented from being withdrawn further by the shuttle assemblyreaching the back of the groove 244.

In FIG. 32 the drawer is now closed in the direction 294, and becausethe shuttle 249 is caught in the notch between 255 and the front frameof the drawer 252, the shuttle assembly 245 stays fixed in spacerelative to the draw frame 252, and so moves to the front relative tothe closing drawer. The serrated lower plate 261 is then put back inposition in the direction 288 using the tab 229, guided up into positionby grooves 255 and 265 riding on the pins 257 and 263, and the plate261. In FIG. 33, the plate 261 is kept in place by closing the door 205and locking it which causes the leaf spring 269 to press on the frontedge 254 of 261. The top edge of the plate, 261, lifts the shuttle 249up off the notch tab 255 to the position 253 return the mechanism to thestate shown in FIG. 25. The drawer is now set for use again

If the restock technician does not have enough product to completelyre-fill the drawer, they will fill from the back. This might leave, forexample, two empty pockets at the front, and the first medication inpocket 3. During the restock process the processor will keep the drawerunlocked. Consequently, starting from the restocked position of FIG. 33,the restock technician will simply open and close the drawer twice toadvance the shuttle, so that the next opening, for a user, will revealthe medication in Pocket 3.

Other mechanisms can be created to implement the method of requiring adrawer to be closed in order to advance the opening position by one,accompanied by a mechanism to reset the drawer after restocking. Onesystem would utilize a belt and onother would utilize a miniature formof bicycle chain.

1. A method for dispensing pharmaceutical or medical supply items from aunit comprising a cabinet having a processor and a plurality ofretractable drawers, which are covered by one or more lockable doors atleast some of the drawers having one or more pockets for holding items,the method comprising: identifying a user that is requesting access tothe pharmaceutical or medical supply items held in the dispensingcabinet by receiving user identification information into the processor;entering pharmaceutical or medical supply item identificationinformation into the processor to identify the items the user wishes toremove from the cabinet; comparing the user identification informationwith an access list having information as to which of the requestedpharmaceutical or medical supply items to which the user may be givenaccess based on the previously entered user identification informationto determine one or more of the locked doors to which the user may begiven access; unlocking one of the doors having have the drawer behindit that contains at least one of the requested pharmaceutical or medicalsupply items if the access list indicates that the user may have accessto the door having the requested pharmaceutical or medical supply item;opening the unlocked door, withdrawing the desired drawer, activating anindicator at the side of the drawer to indicate which row contains thepocket which holds the pharmaceutical or medical supply items that theuser has requested to remove activating an indicator along the front ofthe drawer to indicate which column contains the pocket which holds thepharmaceutical or medical supply items that the user has requested toremove identifying the right pocket by observing the pocket at theintersection of the indicated row and indicated column removing therequested pharmaceutical or medical supply item from the pocket.
 2. Themethod of claim 1 where a second array of row indicators is placed onthe side of the drawer opposite the first so that the row is indicatedat both ends.
 3. The method of claim 1 where a second array of columnindicators is placed on the cabinet frame just above the drawer, so thatthe column of interest is indicated at both ends of the exposed portionof the drawer.
 4. The method of claim 1 where the indicator is a light.5. The method of claim 4 where the indicator is a light emitting diode.6. The method of claim 4 where the light seen bit the user is deliveredby a light pipe.
 7. The method of claim 1 where the indicator is anelectromechanical device that moves a tab such that the color shown ischanged.
 8. The method of claim 1 where the door that is unlocked isshown to be unlocked by a light on the cabinet.
 9. The method of claim 8where that light is aligned to also indicates which drawer to open. 10.The method of claim 1 where at least some of the pockets have lids. 11.The method of claim 10 where at least some of the lids are locked andonly the pocket containing the pharmaceutical or medical supply itemsthat the user has requested to remove is unlocked.
 12. The method ofclaim 1 where the access to a pocket is detected by a sensor or othermeasurement.
 13. The method of claim 12 where the access to the pocketcauses a pre-recorded sound file to be played to the user.
 14. Themethod of claim 12 where the access to the pocket causes text to speechto be played to the user.
 15. The method of claim 12 where the pockethas a lid, the opening of which can be sensed by the processor.
 16. Themethod of claim 15 where the detection mechanism is by an array ofsources and receivers in the Y-row and X-column directions and theopening is detected by the interruption of a row signal and a columnsignal.
 17. The method of claim 12 where the detection mechanism is acapacitance bridge, and the change in capacitance when the fingers of ahand are inserted into the pocket is detected by the change incapacitance.
 18. The method of claim 11 where the locking mechanism isby an array of bars in the Y-row direction and the X-column direction,where the actuation of a specific bar in the row direction and anotherspecific bar in the column direction unlocks a single pocket at theintersection of the row and column.
 19. The method of claim 1 where oneor more video cameras are activated when the user enters theiridentification into the processor, and are deactivated when the user hascompleted the whole transaction.
 20. The method of claim 18 where arecorded video file is made a part of the transaction record stored inthe processor, for later retrieval and review.
 21. A system fordispensing pharmaceutical or medical supply items from a unit comprisinga cabinet having a processor and a plurality of retractable drawers,which are covered by one or more lockable doors at least some of thedrawers having one or more pockets for holding items, the systemcomprising: identifying a user that is requesting access to thepharmaceutical or medical supply items held in the dispensing cabinet byreceiving user identification information into the processor; enteringpharmaceutical or medical supply item identification information intothe processor to identify the items the user wishes to remove from thecabinet; comparing the user identification information with an accesslist having information as to which of the requested pharmaceutical ormedical supply items to which the user may be given access based on thepreviously entered user identification information to determine one ormore of the locked doors to which the user may be given access;unlocking one of the doors having have the drawer behind it thatcontains at least one of the requested pharmaceutical or medical supplyitems if the access list indicates that the user may have access to thedoor having the requested pharmaceutical or medical supply item; openingthe unlocked door, withdrawing the desired drawer, activating anindicator at the side of the drawer to indicate which row contains thepocket which holds the pharmaceutical or medical supply items that theuser has requested to remove activating an indicator along the front ofthe drawer to indicate which column contains the pocket which holds thepharmaceutical or medical supply items that the user has requested toremove identifying the right pocket by observing the pocket at theintersection of the indicated row and indicated column removing therequested pharmaceutical or medical supply item from the pocket
 22. Thesystem of claim 21 where a second array of row indicators is placed onthe side of the drawer opposite the first so that the row is indicatedat both ends.
 23. The system of claim 21 where a second array of columnindicators is placed on the cabinet frame just above the drawer, so thatthe column of interest is indicated at both ends of the exposed portionof the drawer.
 24. The system of claim 21 where the indicator is alight.
 25. The system of claim 24 where the indicator is a lightemitting diode.
 26. The system of claim 24 where the light seen by theuser is delivered by a light pipe.
 27. The system of claim 21 where theindicator is an electromechanical device that moves a tab such that thecolor shown is changed.
 28. The system of claim 21 where the door thatis unlocked is shown to be unlocked by a light on the cabinet.
 29. Thesystem of claim 28 where the light is aligned to also indicates whichdrawer to open.
 30. The system of claim 21 where at least some of thepockets have lids.
 31. The system of claim 30 where at least some of thelids are locked and only the pocket containing the pharmaceutical ormedical supply items that the user has requested to remove, is unlocked.32. The system of claim 21 where the access to a pocket is detected by asensor or other measurement.
 33. The system of claim 32 where the accessto the pocket causes a prerecorded sound file to be played to the user.34. The system of claim 32 where the access to the pocket causes text tospeech to be played to the user.
 35. The system of claim 32 where thepocket has a lid, the opening of which can be sensed by the processor.36. The system of claim 35 where the detection mechanism is by an arrayof sources and receivers in the Y-row and X-column directions and theopening is detected by the interruption of a row signal and a columnsignal.
 37. The system of claim 32 where the detection mechanism is acapacitance bridge, and the change in capacitance when the fingers of ahand are inserted into the pocket is detected by the change incapacitance.
 38. The system of claim 31 where the locking mechanism isby an array of bars in the Y-row direction and the X-column direction,where the actuation of a specific bar in the row direction and anotherspecific bar in the column direction unlocks a single pocket at theintersection of the row and column.
 39. The system of claim 21 where oneor more video cameras are activated when the user enters theiridentification into the processor, and are deactivated when the user hascompleted the whole transaction.
 40. The system of claim 39 where arecorded video file is made a part of the transaction record stored inthe processor, for later retrieval and review.
 41. A method forindicating the pocket containing pharmaceutical or medical supply itemsin a drawer having a plurality of receptacles for holding items, wherethe bins are symmetrically arrayed in rows and columns, the methodcomprising: activating an indicator from an arrays of indicators on theleft side of the drawer to indicate the left-to-right row in which thepocket is located activating an indicator from an array of indicators onthe front side of the drawer to indicate the front-to-back column inwhich the pocket is located identifying the pocket by observing theintersection of the selected row and column.
 42. The method of claim 41where a second row of indicators is arrayed on the right hand side ofthe draw and a second indicator on the same row is activated to identifyboth ends of the row.
 43. The method of claim 41 where a second row ofindicators is arrayed just above the drawer in parallel to the array onthe front of the drawer, and an on this array is activated to identifyboth ends of the column.
 44. The method of claim 41 where the indicatoris a light.
 45. The method of claim 44 where the indicator is a lightemitting diode.
 46. The method of claim 44 where the light seen by theuser is delivered by a light pipe.
 47. The method of claim 41 where theindicator is an electromechanical device that moves a tab such that thecolor shown changes.
 48. A method for detecting access to a receptaclecontaining a pharmaceutical or supply item, the method comprising:placing metal plates in the receptacle to form a capacitor detecting thechange in capacitance of the capacitor when a hand or the fingers of ahand enter the receptacle identifying to a processor that someone isaccessing the receptacle.
 49. The method of claim 48 where the change incapacitance is detected by a bridge circuit.
 50. The method of claim 48where the detection mechanism is analog.
 51. The method of claim 48where the detection mechanism is digital.
 52. The method of claim 48where the detection mechanism is a combination of analogs and digital.53. The method of claim 48 where the bridge circuit is self balancingover time to compensate for changes in capacitance due to dielectricchanges that are not due to a human hand or fingers entering the pocket.54. The method of claim 53 where the balancing occurs more quickly fordecreases in capacitance.
 55. The method of claim 48 where the detectionof the dielectric change only occurs when the processor has recordedthat a user has logged into the computer and that the medicationretrieval process is not finished.
 56. A method for unlocking the lidsof bins containing pharmaceutical or medical supply items in a drawerhaving a plurality of receptacles for holding items, where the bins aresymmetrically arrayed in rows and columns, the method comprising:providing an array of release mechanisms across the width of the drawer,each release mechanism able to lock or unlock all the lids in the rowassociated with that release mechanism providing an array of releasemechanisms from front to back of the drawer, each release mechanism ableto lock or unlock all the lids in the column associated with thatrelease mechanism activating one release mechanism across the width ofthe drawer and one release mechanism from front to back, thus unlockinga single lid at the intersection of that row and column.
 57. The methodof 56 where the release mechanism is a bar activated by a rotatingsolenoid at one end and a rotary bearing at the other end.
 58. Themethod of 56 where the release mechanism is a sliding bar activated by alinear solenoid at each end.
 59. The method of 56 where the means forholding down the lid in locked position is a connected tab thatinteracts with the mechanisms across the width and depth of the drawers.60. A mechanism for unlocking the lids of bins containing pharmaceuticalor medical supply items in a drawer having a plurality of receptaclesfor holding items, where the bins are symmetrically arrayed in rows andcolumns, the mechanism comprising: providing an array of lids with armsextending into the body of the drawer, the end of the arm formed into atab providing an array of release bars from front to back of the drawer,each release bar rotatable through 90 degrees, with notches on the barthat interact with the tab on each lid, such that in one position ofrotation of the bar, all the lids are prevented from opening, and in theother position all the lids can be opened providing an array of releasebars from side to side of the drawer, each release bar rotatable through90 degrees, with notches on the bar that interact with the tab on eachlid, such that in one position of rotation of the bar, all the lids areprevented from openings, and in the other position all the lids can beopened Activating one release mechanism across the width of the drawerand one release mechanism from front to back, to unlock a single lid atthe intersection of that row and column.
 61. The method of 60 where therelease mechanism is a bar activated by a rotating solenoid at one endand a rotary bearing at the other end.
 62. The method of 60 where therelease mechanism is a sliding bar activated by a linear solenoid ateach end.
 63. The method of 60 where the means for holding down the lidin locked position is a connected tab that interacts with the mechanismsacross the width of the drawers.
 64. A mechanism for detecting theopening of lids of bins containing pharmaceutical or medical supplyitems in a drawer having a plurality of receptacles for holding items,where the bins are symmetrically arrayed in rows and columns, themechanism comprising: providing an array of lids with arms extendinginto the body of the drawer, the end of the arm formed into a tabproviding an arrays of light sources on the interior of one side of thedrawer and corresponding light detectors on the interior of the otherside of the drawer from side to side of the drawer, at least some of thelight/detector pairs positioned so that the movement of a lid andassociated tab as the lid is lifted will break the beam of light betweento source and receiver providing an array of light sources on theinterior of the front side of the drawer and corresponding lightdetectors on the interior of the back side of the drawer from front toback of the drawer, at least some of the light/detector pairs positionedso that the movement of a lid and associated tab as the lid is liftedwill break the beam of light between to source and receiver detectingthe lifting of a specific lid by determining the row in which a lightbeam is interrupted and the column in which a light beam is interrupted.65. The method of 64 where the light source is a light emitting diode.66. The method of 64 where the light source is a laser.
 67. The methodof 64 where the detector is a photosensitive cell.
 68. A method forenhancing the safety of an automated pharmaceutical or medical supplydispensing cabinet having a processor the method comprising detectingwhen the user is about to take a specific medication from the cabinetplaying a voice message to the user describing the item the user isabout to take so that the user can confirm they are taking the correctitem.
 69. The method of claim 68 where the voice message is generatedfrom text to speech from data in a file stored in a cabinet associatedprocessor's database in association with the item.
 70. The method ofclaim 68 where the voice message is generated from a digital recordingstored in a cabinet associated processor's database in association withthe item.
 71. The method of claim 68 where the message is played overspeakers that are designed to focus the sound in the direction of theuser's ears.
 72. The method of claim 68 where the volume of the sound isset for each individual user.
 73. The method of claim 68 where the soundis only played for certain high risk medications in the cabinet.
 74. Themethod of claim 68 where the sound is only played for certain users ofthe cabinet.
 75. A method for enhancing the security of an automatedpharmaceutical or medical supply dispensing cabinet the methodcomprising beginning a video recording of the user's actions with acamera attached to the cabinet and in connection with the processor inthe cabinet detecting the completion of the users actions at the cabinetstoring the video recording in the processor as a file associated withthe transaction record of the items requested by the user.
 76. Themethod of claim 75 where the camera records the user's face.
 77. Themethod of claim 75 where the camera is facing downward to record theusers hands in accessing pockets containing pharmaceuticals in a drawerwithdrawn from the cabinet.
 78. A method for issuing single doses ofmedication from an automated medication dispensing cabinet, the methodcomprising identifying a user that is requesting access to thepharmaceutical or medical supply items held in the dispensing cabinet byreceiving user identification information into the processor; enteringpharmaceutical or medical supply item identification information intothe processor to identify the items the user wishes to remove from thecabinet; unlocking a modular drawer containing multiple doses of arequested medication allowing the drawer to open to reveal a firstsmedication dose removing that dose requiring the drawer to be closedcompletely to cause the drawer to open to reveal a second medicationeither to the same user or to the next user.
 79. The method of claim 78where the processor re-locks the drawer on closing, thus allowing theuser to take only one medication.
 80. The method of claim 78 where theprocessor uses a sensor to detect the complete closing of the drawer tocount how many medications the user has taken, thus allowing theprocessor to re-lock the drawer after the user has taken the requestednumber, and no more.
 81. The method of claim 78 where the mechanism thatallows the drawer to open one more pocket after it has been closed is ashuttle that advances one position on each complete drawer closing overa serrated late.
 82. The method of claim 78 where the mechanism thatallows the drawer to open one more pocket after each closing is anotched belt.
 83. The method of claim 78 where the mechanism that allowsthe drawer to open one more pocket after each closing is a miniaturebicycle chain.
 84. A system for issuing single doses of medication froman automated medication dispensing cabinet, the system comprisingentering user identification information into the processor identifyingthe user that is requesting access to the pharmaceutical or medicalsupply items held in the dispensing cabinet entering pharmaceutical ormedical supply item identification information into the processor toidentify the items the user wishes to remove from the cabinet; unlockingat least one modular drawer containing multiple doses of a requestedmedication opening the drawer which causes a shuttle mechanism toadvance to a new locking position to reveal a first medication doseremoving that dose closing the drawer completely which causes theshuttle mechanism to drop to a new position which will now allow thedrawer to open to reveal the next pocket and medication when it iswithdrawn.
 85. The system of claim 84 where the processor uses anelectronic lock mechanism to re-lock the drawer on closing, thusallowing the user to take only one medication.
 86. The system of claim85 where the locking mechanism is a latch and a solenoid.
 87. The systemof claim 84 where the processor uses a sensor to detect the completeclosing of the drawer to count how many medications the user has taken,thus allowing the processor to re-lock the drawer after the user hastaken the requested number, and no more.
 88. The system of claim 87where the sensor is optical.
 89. The system of claim 87 where the sensoris a Hall effect device.
 90. The system of claim 84 where the mechanismthat allows the drawer to open one more pocket after it has beencompletely closed is a shuttle that advances one position on eachclosing over a serrated plate.
 91. The method of claim 84 where themechanism that allows the drawer to open one more pocket after eachclosing is a notched belt.
 92. The method of claim 84 where themechanism that allows the drawer to open one more pocket after eachclosing is a miniature bicycle chain.